This invention relates to tools and methods for aligning and assembling workpieces, and more particularly relates to such tools and methods for aligning and assembling a poly-plane workpiece and a base member along their central axes.
A single panel scrolling color projection display system is characterized by a single light modulator panel such as a liquid crystal display (LCD) panel having a raster of individual picture elements or pixels, which panel is illuminated by horizontally elongated red, green and blue illumination bars or stripes. The stripes are continuously scrolled vertically across the panel while the illuminated rows of pixels are synchronously addressed with display information corresponding to the color of the then incident stripe. See, for example, U.S. Pat. No. 5,410,370, “Single panel color projection video display improved scanning” issued to P. Janssen on Mar. 25, 1994, and U.S. Pat. No. 5,416,514, “Single panel color projection video display having control circuitry for synchronizing the color illumination system with reading/writing of the light valve” issued to P. Janssen et al. on May 16, 1995.
Light engines for such single-panel color projection display systems commonly utilize spinning prisms to generate the scrolling illumination bars or stripes. These prisms typically are polyhedrons having four plane sides substantially parallel to a central axis of rotation, and a square cross-section. Although the prisms must be centered with great precision to the axis of rotation of the scanner motor, this is difficult in practice due to the large dimensional tolerances associated with a low-cost manufacturing process.
This centering is presently carried out by clamping the prism into the chuck of a lathe, measuring the (lateral) runout, adjusting the chuck and again measuring the runout. This process is repeated until the prism is centered within tolerance. Next, adhesive is applied to the end face of the prism adjacent to the rotor. The latter is held centered (by its shaft) in the lathe's stock. The stock is then moved forward until contact is made between the rotor and the prism is made. After the adhesive is cured, the assembly is released. This method tends to be cumbersome and time-consuming, and is thus unattractive for producing a large number of prism/rotor assemblies.